Split housing for circuit breakers held together by resilient clip



July 9, 1957 W FEW ErAL SPLIT HOUSING FOR CIRCUIT BREAKERS'HELD TOGETHERBY RESILIENT CLIP Original Filed March 51, 1951 IN VEN TORS', WILLIAMFEW AND BY ARALD B. PEARSON l WMM ma@ United ."Statesl Patent C iSPLI'I` HOUSING FR CIRCUIT BREAKERS HELD TOGETHER BY RESlLlENT CLIPWilliam Few, Goshen, 1nd., and Arald B. Pearson, East Cleveland, (Ehio,assignors to The Clark Controller Company Original application March 31,1951, Serial No. 218,626, now Patent No. 2,692,318, dated October 19,1954. Divided and this application April 13, 1954, Serial No. 422,748

4 Claims. (Cl. Z60m-168) This invention relates in general to electriccircuit breakers or switches and more particularly to the constructionof a split insulating housing or arc chamber held together by resilientclip. This application is a division of applic-ation, Serial No.218,626, tiled March 3l, 1951 for Arc Chamber for Circuit Breakers, nowPatent No. 2,692,318, October 19, 1954.

An object of the invention is the provision of a split insulatinghousing comprising an insulating support member and a readily removableinsulating body member having an arc chamber kfor an electric switchtaken in combination with a resilient clip means for holding theremovable insulating body member to the insulating support member.

Another object of the invention is the provision of resilient clip meansfor holding the removable insulating body member to the insulatingsupport member in which the resilient clip means comprises a coil springsupported between two spaced locations on the insulating support memberand engaged between said two spaced locations by a latch member whichremovably engages the removable insulating body member.

Another object of the invention is the combination of a latch membermounted to a portion of a coil spring supported between two spacedlocations whereby the resiliency of the combination is obtained by thelateral give of the portion of the coil spring between the two spacedlocations.

Other objects and a fuller understanding of the invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawing, in which:

Figure 1 is a front elevational view of the invention with certain partsbroken away to illustrate more clearly the construction of the arcchamber and the contact means, the resilient clip being shown in dottedlines;

Figure 2 is a side elevational View of the device shown in Figure 1,taken along the line 2-2 thereof;

Figure 3 is a View taken along the split between the insulating supportmember and the readily removable insulating body member, and showing theface of the insulating support member with the stationary contact meansappearing thereon; and

Figure 4 is a side elevational View of the device shown in Figure l, andshows particularly the arrangement of the resilient clips for holdingthe removable insulating body member against the insulating supportmember.

With reference to the drawings, the circuit breaker or switch isdesignated generally by the reference character 12 and is arranged to beoperated by an actuating electromagnet indicated by the referencecharacter 13.

The switch 12 and the actuating electrom-agnet 13 may be mounted on abase having lholes 11 therein to facilitate the anchoring of the entireassembly to a suitable support or closure box or housing. The actuatingelectromagnet 13 may be of any suitable design or conice the conductors50, and acts to close the circuit breaker 12 when energized. Theelectromagnet 13 has an operating member 47 extending upwardly Ifrom theupper side thereof. As illustrated, the operating member 47 is in itslower or retracted position, being the position when the electromagnetis de-energized and the switch open. The downward travel of theoperating member 47 opens the contacts and is arrested by means of acollar 48 engaging the upper surface of the electromagnet.

In the drawings, the switch 12 or circuit breaker is arranged tointerrupt a three-phase circuit by three sets of contacts designated,respectively, as A, B and C, disposed in a split insulating housing. Theset of contacts A, B and C for the respective phases of the electriccircuit are of the same construction and corresponding parts bear thesame reference characters. As shown, each set of contacts is arranged toproduce a double break in struction and is arranged to be electricallyenergized by the electrical circuit and comprises two stationary contactmeans 18 and 19 and two movable contact means 20 and 21. The contactmeans 18 and 20 comprise one pair of contacts and the contact means 19andy 21 are disposed closer to the base 10 than the contact meansconsisting of rthe contact means 18 and 20. The movable contact means 20and 21 are connected together by a bridge member 53. As illustrated bestin Figure l, the bridge members 53 for the respective sets of contactsA, B and C are arranged to be simultaneously actuated by a motiontransmitting means, which is illustrated by the dash-dot lines 14 andwhich is actuated by the operating member 47 of the actuatingelectromagnet 13.

Each of the pairs of contacts is arranged to be interrupted in a splitinsulating housing comprising two parts 22 and 23. The part 22 comprisesan insulating support member and the part 23 comprises a removableinsulating body member adapted to be detachably connected to theinsulating support member by means of resilient clips 45. The insulatingsupport member and the insulating body member have mating wall surfaces16 and 17, respectively, abutting each other and forming tne splitbetween the members. The insulating split housing has individual arcchambers for each of the pair of separable contacts. The arc chambersare all identical and the construction is such that a part of the arcchamber is in the insulating support member 22 and the other part is inthe insulated body member 23. inasmuch as the construction of the arcchambers are all identical, the description will be in the singular Iforone of the chambers.

The insulating support member 22 has six cavities 30, one each for thearc chambers. The cavity 30 has a back wall 32 and an annular wall 33,comprising four sides defining a first portion of the chamber on therear side of the split between the insulating support member 22 and theinsulating body member 23. The removable insulating body member 23 hassix cavities 66, one each for the arc chambers. Each of the cavities 66comprises an annular wall 67 having four side surfaces dening a secondportion of the chamber on the opposite side of the split between theinsulating support member and the removable insulating body member. Thefour sides of the cavity 30 and the cavity 66 are respectively of thesame size and register with each other to form the arc chamber. Theremovable insulating body member 21 also has an opening 68 extendingfrom the second portion of the arc chamber to the outside thereof inwhich the movable contact means moves.

Mounted within the cavity 311 of the insulating support member 22 is acup-shaped member 63 having a bottom or end portion 64 abutting againstthe back wall 32 of the cavity. The cup-shaped member 63 is constructedof magnetic material and comprises a shell mounted in the cavity 30. Onthe inside bottom of the cup-shaped member 63 is an insulating plate 60having a centrally disposed hole which is in alignment with a hole 52 inthe back end wall of the cup-shaped member 63.

A post element 36 constructed of magnetic material and being in the formof a bolt having a head 38 is mounted on the insulating support member22 and has a projection portion 39 extending through the hole S2 of thecup-shaped member 63 and the hole of the insulating plate 60 into thearc chamber. The post element 36 is smaller than the hole 52 in the backwall of the cupshaped member 63 and is radially spaced and electricallyinsulated therefrom. Upon the end of the projection portion 39 ismounted the stationary contact means. The projection portion 39 of thepost element 36 supports the stationary contact means in the secondportion of the chamber beyond the split between the insulating supportmember 22 and the insulating body member 23, whereby the stationaryContact means is readily accessible upon removal of the insulating bodymember 23 from the insulating support member 22. The post element 36defines, in combination with the rst annular internal wall 33 of thecavity 3i), an annular recess 42 having an open end 43 terminatingsubstantially at the split between the insulating support member 22 andthe insulating body member 23. Mounted within the annular recess 42 is amagnetizable winding or blow-out coil 56 which surrounds the postelement 36. The magnetizable winding 56 has a terminal lead 55 whichextends rearwardly through an opening in the back wall of the insulatingsupport member 22. The terminal 55 extends to the outside of theinsulating support member 22 and on the end thereof is mounted aterminal screw clamp 58 constituting a conductor terminal for connectingthe magnetizable winding to an external circuit. The forward end of themagnetizable winding 56 which is in the form of a flat coil iselectrically and mechanically connected to the rear side of a plate 52?by soldering, brazing or other means. The area of the plate 59 isgreater than that of the stationary contact means and thus it restrictsthe entrance to the annular recess 42 whereupon foreign particles causedby the arc are prevented from entering the recess and coating the insidesurface therein, particularly the insulating plate 66. An object ofpreventing the foreign particles from entering the recess is to keep theinside of the arc chamber and the insulating plate 60 clean.

The plate 59 on diagonally opposite corners is provided with lateralportions 80 and 81 having ends that contact the inside surface of thecavity 3i). The ends of the laterally disposed extension portions 80 andS1 which engage the inside surface of the cavity 30 align the postelement 36 and the magnetizable winding 56 within the annular recess sothat when the stationary contact means is screwed onto the end of thepost element, the parts are maintained in straight and xed alignment.The stationary contact means can be removed from the end of the postelement without removing the magnetizable winding or blow-out coil 56.The plate 59 is permanently connected to the end coil of themagnetizable winding 56, so that when the stationary contact means isscrewed tightly against the outer face of the plate 59, a low resistancecontact is established. ln addition, the plate 59 constitutes a heatradiation member to keep the contact means cool.

Mounted within the cavity 66 of the insulating body member 23 is acup-shaped member S5. The cup-shaped member 85 is of the same generalconstruction as the cup-shaped member 63 and is constructed ofmagnetizable material. The cup-shaped member 85 is securely mounted ormolded within the cavity 66 of the insulating body member 23 so thatupon removal of the insulating body member 23 from the insulatingsupport member 22, the cup-shaped members 85 remain permanently lixedtherein. The end wall of the cup-shaped member 85 is provided with ahold S6 in alignment with the opening 68 in which the movable contactmoves. The cup-shaped member 85 and the cup-shaped member 63 constitutea portion of the magnetic circuit along with the post member 36 forproviding the ux for controlling the arc. The action of the tlux is suchto keep the inside of the arc chamber clean so that the insulating plate60 is kept clean.

The removable insulating support body member 23 may be easily removed byoperating the resilient clips 45 which have at their forward ends a hook46 for e11- gaging a ledge in the front side of the removable insulatingbody member 23. The other ends of the clips 45 are hingedly connectedrespectively to coil springs 98 which are mounted in longitudinallyextending holes 99 in opposite sides of the insulating support member23. The sides of the insulating support member 23 are provided withslots to receive the hinged ends of the clips 45 which means that thecoil springs 98 are held between two spaced points at the hingedconnection so that there is a certain amount of resiliency to thatportion of the coil springs between the spaced points when operating theclips 45.

The insulating housings 22 and 23 are preferably constructed of materialwhich will withstand high temperatures caused by the heat from the arc.However, if the arc is permitted to come directly in contact with theinsulating material there might be a tendency for the material todecompose and form ne foreign particles of carbon which might tend towork their way into the arc chamber. In the event that ne carbonparticles are formed by the temperature of the arc deteriorating theinsulating members, the two metal cup-shaped members 63 and 85 which titwithin the arc chamber formed by the insulating materials willconstitute a mechanical barrier to make it difficult for the ne carbonparticles to work their way into the arc chamber. In addition, the twometal cup-shaped lmembers are in themselves good heat conductors andthus any heat from the arc is well distributed throughout the entiresurface areas thereof, so that there is no one point of highconcentration of heat directly affecting the insulating material.

It is to be observed that a small peripheral clearance lill existsbetween the outside surface of the cup-shaped member 63 and the insideannular surface of the cavity 30. This clearance may be in the order of.002 of an inch up to substantially .015 of an inch. One object of thisannular clearance between the outside surface of the cupshaped member 63and the internal wall of the cavity 30 is to prevent the heat of the arcwhich is transmitted to the metal cupfshaped member from being directlytransmitted to the inside surface of the walls of the insulating housingof the cavity 30.

Although this invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and the scope of the invention as hereinafterclaimed.

What is claimed is:

l. A split housing having a chamber for a switch comprising stationarycontact means and movable contact means, said split housing comprisingan insulating support member and a readily removable insulating bodymember having mating wall surfaces extending transversely of saidchamber and constituting the split between said member, said insulatingsupport member having a first annular wall defining a first portion ofsaid chamber on one side of said split, said removable insulating bodymember having a second annular wall dening a second portion of saidchamber on the opposite side of said split, said removable insulatingmember also having an opening extending from the second portion of saidchamber to the outside thereof in which the movable contact means moves,clip means for holding said insulating members together, said clip meansincluding a latch element engaging one of said members and a hingesupport means carried by the other member, said hinge support meanscomprising a coil spring held between two spaced portions on said othermember, said latch element engaging said hinge support means betweensaid two spaced portions, a post element of magnetic material mounted onthe insulating support member and having a projection portion extendinginto said chamber, said projection portion of said post elementsupporting said stationary contact means on the end thereof beyond saidsplit in the second portion of said chamber, whereby said stationarycontact means is readily accessible upon removal of the insulating bodymember from the insulating support member, said post element deiining incombination with the first annular internal wall of the chamber anannular recess having an open end terminating substantially at saidsplit, magnetizable winding means mounted in the annular recess andsurrounding the post element, a member constituting a shell of magneticmaterial mounted in the annular recess and surrounding the magnetizablewinding means and the post element, and a plate for said open end ofsaid annular recess, said plate comprising an area greater than the areaof said stationary contact means and restricting the entrance to saidannular recess.

2. A clip for holding two body members together, said clip having alatch member having rst and second end portions, said iirst end portionhaving means for removably engaging one of said body members, resilientmeans for connecting said second end portion of the latch member to theother body member, said resilient means comprising a coil springsupported between two spaced locations on said other body member, saidsecond end portion of the latch member engaging the coil spring betweensaid two spaced locations.

3. A split housing having a chamber for a switch comprising stationarycontact means and movable contact means, said split housing comprisingan insulating support member and a readily removable insulating bodymember having mating wall surfaces extending transversely of saidchamber and constituting the split between said member, said insulatingsupport member having a first annular wall defining a iirst portion ofsaid chamber on one side orr said split, said removable insulating bodymember having a second annular wall deiining a second portion of saidchamber on the opposite side of said split, said removable insulatingmember also having an opening extending from the second portion of saidcharnber to the outside thereof in which the movable contact meansmoves, and clip means for holding said insulating members together, saidclip means including a latch element engaging one of said members and ahinge support means carried by the other member, said hinge supportmeans comprising a coil spring held between two spaced portions on saidother member, said latch element engaging said hinge support meansbetween said two spaced portions.

4. A split housing having a chamber for a switch comprising stationarycontact means and movable Contact means, said split housing comprisingan insulating support member and a readily removable insulating bodymember having mating wall surfaces extending transversely of saidchamber and constituting the split between said member, and clip meansfor holding said insulating members together, said clip means includinga latch element engaging one of said members and a hinge support meanscarried by the other member, said hinge support means comprising a coilspring held between two spaced portions on said other member, said latchelement engaging said hinge support means between said two spacedportions.

References Cited in the tile of this patent UNITED STATES PATENTS

